Observational study for the evaluation of clinical effectiveness in daily clinical practice of inhaled combination of propionic Fluticasone and Salmeterol in doses (500+50)mcg - Rolenium- administered with Elpenhaler device in approximately 2000 COPD (Chronic Obstructive Pulmonary Disease) patients with a FEV1 <50% predicted normal (pre-bronchodilator), a history of repeated exacerbations and who have significant symptoms despite regular bronchodilator therapy in Greece.